/*
 * Copyright 2015-2016 RonCoo(http://www.roncoo.com) Group.
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.marketing.common.util;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
 * MD5加密，使用UTF-8编码
 *
 * @author wujing
 */
public final class MD5Util {
	private static Logger logger = LoggerFactory.getLogger(MD5Util.class);

	private MD5Util() {
	}

	/**
	 * Used building output as Hex
	 */
	private static final char[] DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e',
			'f' };

	/**
	 * 对字符串进行MD5加密， 默认使用UTF-8
	 * 
	 * @param text
	 *            明文
	 * @return 密文
	 */
	public static String MD5(String text) {
		return MD5(text, "UTF-8");
	}

	/**
	 * 对字符串进行MD5加密
	 * 
	 * @param text
	 *            明文
	 * @param charsetName
	 *            指定编码
	 * @return 密文
	 */
	public static String MD5(String text, String charsetName) {
		MessageDigest msgDigest = null;
		try {
			msgDigest = MessageDigest.getInstance("MD5");
		} catch (NoSuchAlgorithmException e) {
			logger.error(e.getMessage(), e);
			throw new IllegalStateException("System doesn't support MD5 algorithm.");
		}
		try {
			msgDigest.update(text.getBytes(charsetName)); // 注意是按照指定编码形式签名
		} catch (UnsupportedEncodingException e) {
			logger.error(e.getMessage(), e);
			throw new IllegalStateException("System doesn't support your  EncodingException.");
		}
		byte[] bytes = msgDigest.digest();
		return new String(encodeHex(bytes));
	}

	private static char[] encodeHex(byte[] data) {
		int l = data.length;
		char[] out = new char[l << 1];
		for (int i = 0, j = 0; i < l; i++) {
			out[j++] = DIGITS[(0xF0 & data[i]) >>> 4];
			out[j++] = DIGITS[0x0F & data[i]];
		}
		return out;
	}

	public static String getSha1(String str) {
		if (null == str || 0 == str.length()) {
			return null;
		}
		char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
		try {
			MessageDigest mdTemp = MessageDigest.getInstance("SHA1");
			mdTemp.update(str.getBytes("UTF-8"));

			byte[] md = mdTemp.digest();
			int j = md.length;
			char[] buf = new char[j * 2];
			int k = 0;
			for (int i = 0; i < j; i++) {
				byte byte0 = md[i];
				buf[k++] = hexDigits[byte0 >>> 4 & 0xf];
				buf[k++] = hexDigits[byte0 & 0xf];
			}
			return new String(buf);
		} catch (NoSuchAlgorithmException e) {
			logger.error(e.getMessage(), e);
		} catch (UnsupportedEncodingException e) {
			logger.error(e.getMessage(), e);
		}
		return null;
	}
	/**
	 * MD5数字签名  小写
	 * 
	 * @param src
	 * @return
	 */
	public static String MD5Encode(String sourceString) {
		String resultString = null;
		try {
			resultString = new String(sourceString);
			MessageDigest md = MessageDigest.getInstance("MD5");
			resultString = byte2hexString(md.digest(resultString.getBytes()));
		} catch (Exception ex) {
		}
		return resultString;
	}

	/**
	 * MD5数字签名  大写
	 * 
	 * @param src
	 * @return
	 */
	public static String md5Digest(String src) {
		String s = "";
		try {
			// 定义数字签名方法, 可用：MD5, SHA-1
			MessageDigest md = MessageDigest.getInstance("MD5");
			byte[] b = md.digest(src.getBytes(UTF8));
			s = byte2HexStr(b);
		} catch (Exception ex) {
		}
		return s;
	}

	public static final String byte2hexString(byte[] bytes) {
		StringBuffer buf = new StringBuffer(bytes.length * 2);
		for (int i = 0; i < bytes.length; i++) {
			if ((bytes[i] & 0xff) < 0x10) {
				buf.append("0");
			}
			buf.append(Long.toString(bytes[i] & 0xff, 16));
		}
		return buf.toString();
	}

	/**
	 * 字节数组转化为大写16进制字符串
	 * 
	 * @param b
	 * @return
	 */
	private static String byte2HexStr(byte[] b) {
		StringBuilder sb = new StringBuilder();
		for (int i = 0; i < b.length; i++) {
			String s = Integer.toHexString(b[i] & 0xFF);
			if (s.length() == 1) {
				sb.append("0");
			}
			sb.append(s.toUpperCase());
		}
		return sb.toString();
	}

	private static final String UTF8 = "utf-8";

	/**
	 * BASE64编码
	 * 
	 * @param src
	 * @return
	 * @throws Exception
	 */
	@SuppressWarnings("restriction")
	public static String base64Encoder(String src) throws Exception {
		BASE64Encoder encoder = new BASE64Encoder();
		return encoder.encode(src.getBytes(UTF8));
	}

	/**
	 * BASE64解码
	 * 
	 * @param dest
	 * @return
	 * @throws Exception
	 */
	@SuppressWarnings("restriction")
	public static String base64Decoder(String dest) throws Exception {
		BASE64Decoder decoder = new BASE64Decoder();
		return new String(decoder.decodeBuffer(dest), UTF8);
	}

	public static void main(String[] args) {
		System.out.println(DateUtil.dateFormat("2018/01/09 14:37", "yyyy/MM/dd HH:mm:ss"));
		System.out.println(md5Digest("123456"));
	}
}
